Pre-corruption Horus appearances

I like old school Horus a lot, read the first HH trilogy several times since they first came out, then stopped keeping up with the series after Descent of Angels.

What I'm looking for are flashback type of things, like in Fear to Tread where the Luna Wolves and Blood Angels are fighting the Nephilim and Horus is in all his glory ("We will be the anvil - now behold the hammer!" cue Sanguinius dropping like a meteor into the battle). Some of these books seem to have those passages/chapters where they skip back in time to give you some back-story.

Any of the books/short stories show Horus as he was, however brief the depiction?

Cheers, Lupercal.